Some topics refuse to fit in a single article.
You know the type. You start writing about testing, and three thousand words later you realise you've only covered the prerequisites. Some subjects are like that colleague who says "quick question" and then talks for forty-five minutes — they need room to breathe.
These series are designed to be read in order. Each part builds on the last, like layers in a well-architected system — except these actually have documentation. More are in the works. Subscribe to the newsletter if you want to know when they land.